# #Mon Aug 09 11:52:47 CEST 2010 Slide__2sSZYKObEd-WfYQ0GneCwQ_subTitle=Electrons may be accelerated in the TESLA hollow resonator to almost the speed of light. In the flight direction, they 'see' therefore the spatial structures, and thus the fields as well by which they are guided themselves, strongly foreshortened - an effect of the Special Theory of Relativity. This bears an important consequence\: Since the electron clouds are moved closer and closer by the cavity field during acceleration, it are disk-shaped electron packages that ultimately leave the accelerating line. Slide__2sSZYKObEd-WfYQ0GneCwQ_title=Relativistic Length Contraction

Slide__2sSZYKObEd-WfYQ0GneCwQ_footer=Source\: Deutsches Elektronen-Synchrotron DESY